Fields of application of the invention include stabilization and arthrodesis of segments of the vertebral column in degenerative pathologies of the spine.
Systems for stabilizing the vertebral column by bracing at least two consecutive vertebrae by means of anchor members fixed into said vertebrae and connected by rigid connecting rods are well known in the art. Systems of this kind are generally coupled systems such that two consecutive vertebrae are interconnected by two substantially parallel rods fixed one on each side of the spinous processes. The anchor members are screwed into the posterior portions of the vertebrae and pass through the pedicles and a substantial portion of the vertebral bodies and therefore provide a fixed and durable connection.
The above stabilizing systems are routinely used to consolidate several consecutive vertebrae. Thus the vertebrae are interconnected by rigid rods over a substantial length of the vertebral column. Such assemblies hold the vertebrae correctly relative to each other; however, they considerably stiffen the spine in terms of bending. It has been shown that a more flexible stabilizing system, which confers greater relative mobility on the vertebrae, is beneficial in some pathologies.